Thin film heads, by necessity, are high tolerance elements which are used to read/write information on various magnetic media, such as high-speed magnetic discs. Presently, the pole pieces of these magnetic heads, which are the elements used to interface with the magnetic media, have not been controlled so as to ensure uniform width and precise alignment of individual poles in any particular pole pair.
Although uneven poles have not presented a serious problem in the use of thin film heads with current magnetic media in currently marketed disc drive systems, future higher areal density applications will require much more stringent head dimensional tolerances. For example, in the not too distant future, magnetic recording disc systems having upwards of a thousand tracks per inch will be employed. Such systems will, in all likelihood, present a physical configuration wherein the track width of readable information will be only 0.8 mils or less. Uneven and/or improperly aligned poles will be unable to interface with the media in these systems without encountering cross-track noise in the read cycle and error-producing signals in the write cycle.
Due to the rather fine tolerances of the pole pieces, it has proven to be extremely difficult to produce pole pairs of substantially equal width and precise alignment relative to each other. It must be remembered that in currently marketed disc drive systems, the average magnetic head pole is only approximately 70-120 micro inches in thickness and approximately 0.9-1.4 mils in width. Prior to the present invention, attempts to produce poles of equal width and precise alignment have relied simply upon trial and error and random fabrication variables which certainly will not be acceptable as tolerances become more exacting with anticipated high density magnetic system applications.
It is thus an object of the present invention to produce pole tips for magnetic heads which are capable of satisfactorily operating with future high density magnetic media applications.
It is still another object of the present invention to provide a method for substantially completely aligning parallel pairs of pole tips for use in magnetic heads.
It is yet another object of the present invention to provide a relatively simple and convenient method of producing parallel pole tip pairs which are substantially of equal length for use in magnetic heads.
These and other objects of the present invention will be more fully appreciated when considering the present disclosure and appended drawings.